When audience participation merges with public art, the potential for squirmishness intensifies – but some brave examples such as the Fourth Plinth in Trafalgar Square and various flash mobs across the UK have shown sometimes you can rely on the public to lose their inhibitions and take part.

Now, the Office of the Mayor of London, along with several other sponsors, has put up a website featuring the possible choices for the next artwork to be displayed on the Fourth Plinth and have invited the public to speak up for their favorite choice.

Pick up a cab in Trafalgar Square, mention the K-word and the mayor will be the single reason that "bendy buses" and "bloody immigrants" are in your way – and that the Fourth Plinth around Nelson's Column, where statues of other war heroes ought to be, is a place for disability campaigners and "arty glass."